The residents of Tree Hill must deal with the aftermath of the bridge accident. Two made it out unharmed while one lands in a coma. In the midst of all the chaos, Dan extends his help to Karen now that she is pregnant. Lucas and Peyton's bond keeps growing stronger and stronger. Former rivals, Brooke and Rachel move past their differences and move in with each other. Brooke makes a definitive decision about her relationship with Lucas. Skills decides to try out for the Ravens.^[2]

It's her eighteenth birthday, but Brooke soon realizes that she has no one but Rachel to celebrate it with. Meanwhile, Nathan continues to struggle with memories of the accident. Dan continues to be haunted by remorse over his actions against Keith.

Peyton spends more time getting to know her newfound brother, Derek. Lucas decides to stop pursuing Brooke as he once again gets close with Peyton. Haley and Nathan try to move forward with their relationship after the accident, but this attempt is quickly ruined as Rachel persistently tries to pursue Nathan. Dan feels an overwhelming amount of guilt over the death of his brother.

Peyton introduces a hip-hop sensation at Tric. Vicious rumors that Brooke is pregnant run rampant. Still dealing with their car accident, Nathan buys a motorcycle despite Haley's reservations, and Rachel poses for Maxim magazine. Meanwhile, Lucas clashes with Derek, and Deb double-crosses Karen.

Nathan gets two surprises of the different variety. Brooke has reasons to celebrate. Peyton learns her "brother" Derek's true nature, and with Lucas's help is doing everything she can to avoid him.

Knee high in debt and almost homeless, Nathan is forced to reach out to his estranged father for help. Brooke and her one night stand run into each other again in surprising circumstances. Peyton gets help from an unexpected source. Lucas returns to the Ravens just in time to help the team advance in the playoffs for the state championship.

Peyton tries to go back to normal, but still has PTSD from Psycho Derek. Brooke's fashions are a hit at the local show. Nathan is cornered into a no-win situation by Daunte. Deb takes drastic action to support her addiction.

Derek tells Peyton to give Lucas a chance just as Brooke tries to make up with him. Nathan continues to have trouble with Daunte. Rachel asks Haley to tutor her when she discovers she is failing a class.

Residents of Tree Hill are feeling the pressure of the state championship and Whitey's final game. Meanwhile, Karen is battling Deb tooth and nail to stay sober in time for Nathan's game. Dan makes an effort to get Daunte to back off of Nathan. Haley discovers the gender of her baby. The long-running love triangle between Peyton, Lucas and Brooke finally comes to a definitive end. When he thinks all of his problems are dealt with, Nathan is dead wrong when he is hit with another traumatic event.

While in a coma, Lucas has a dream in which the spirit of Keith visits and shows him how much one life can affect the lives of others, in a nod to "It's a Wonderful Life". Haley is the victim of Nathan's greedy deal with Daunte, but Dan step in to help.

Three weeks have passed, and the aftermath of the events that happened the night of the championship is still being felt. Lucas returns to his everyday life and tries to rekindle his relationship with Peyton. However, things are rougher for Haley when she discovers that Nathan was more involved in her accident than she could have ever imagined.

Haley is frustrated over her injuries. Skills and Mouth help Nathan earn some extra money as an amateur stripper. Brooke betrays Rachel to get with a new guy. Lucas and Peyton finally find happiness in their relationship.

A senior class assignment pairs students up to get know each other better, and it uncovers what they went through during their 3 years of high school, personal ambitions, but also some personal demons that they are forced to face before the bell rings.^[14]

Haley confronts Brooke regarding the stolen calculus test. Lucas and Peyton consider taking their relationship to the next level. Peyton and Brooke try to push past everything to salvage the friendship they once had. With Deb gone and him being away from the party scene for awhile, Nathan decides to host his final senior party, but when a tape of a wild Nathan during his sophomore year resurfaces that leaves everyone speechless.

In the explosive winter finale, it's the day of the Prom, and tensions are running high in Tree Hill. An emotional Haley confronts Nathan about the sex tape and asks for a list of all his past sexual encounters. Peyton decides to skip the dance, but Lucas decides to wait for her. Brooke and Peyton let out all their frustrations in a confrontation that puts a further strain on their tumultuous friendship. The day reaches an all time boiling point when a certain someone has their life in danger.

In the spring premiere, prom night has arrived for the seniors of Tree Hill high, but things start to go awry. Lucas remembers that someone was in the hallway when Keith was killed. Psycho Derek holds Peyton and Brooke hostage in Peyton's own house. Haley and Nathan vow to be romantic evening despite unforeseen circumstances. Dan continues to win over Karen's affections. Within Reason guest star to perform during the Prom.

A week has passed since the eventful night that was Prom, and Mouth has finally reached out for help after leaving town with Rachel. As the gang rescue him from a small hole in the wall town, Honey Grove, Texas, they get a second chance to have a perfect prom. During the night, Lucas and Peyton decide to take their relationship to the next step and Brooke confesses to Haley a long held secret.

With Rachel gone, Brooke and Peyton finally rekindle their friendship. Nathan's past mistakes continue to haunt him and Haley. Lucas finds the witness of the day of the school shooting and hears a shocking confession.

As the end of the school year approaches, Peyton considers accepting a music internship in Los Angeles. Brooke tries to reconnect with Chase through yearbook signatures. Due to Nathan's past mistake, Haley's valedictorian position is threatened. Dan suggests that Lucas get professional help when Karen continues to worry about his obsession with theories about Keith's death

As graduation approaches, Haley prepares for the recital of her valedictorian speech and motherhood. Nathan and Brooke make huge decisions that could cost them their futures. Lucas confronts Dan after Karen's life is threatened. Karen gives birth to her daughter. The song "Times Like These" from the Foo Fighters is heard during the graduation scene.^[22]

2 weeks have passed since graduation, Dan faces the harsh reality of his sins both past and present. Nathan and Haley struggle on their first night out after the baby. While Rachel returns and hosts a graduation party where the gang celebrate and reminisce about their high school journey and prepare for the next chapter of their lives.